Accessing the paylod in the Callback constraint

[xabbuh]

Since Symfony 2.6 it is possible to pass custom payload data to the constraint validators. However, it was not possible to access this payload in the Callback constraint. With Symfony 3.1 this will now be possible as the payload is passed as an additional argument to the callback (see symfony/symfony#16909).

[wouterj]

This new parameter to the callback should be documented in http://symfony.com/doc/current/reference/constraints/Callback.html (at least, all examples should be updated to have a $payload parameter as last parameter)

[jorgelbg]

The payload option is documented on http://symfony.com/doc/current/reference/constraints/Callback.html, but the examples indeed are not taking this parameter. If it's ok I'll try to update the examples.

[jorgelbg]

I think it would be a great addition at least one example that actually uses the $payload parameter. Any thoughts?

[wouterj]

@jorgelbg hmm, I can't come up with a nice example as well... For now, I have merged #6593 and you can create a new PR as soon as we find a nice example.